A.T. Robertson Commentary John 12:28

"Father, glorify thy name. There came therefore a voice out of heaven, [saying], I have both glorified it, and will glorify it again." — John 12:28 (ASV)

Father, glorify thy name (πατερ, δοξασον σου το ονομα). First aorist (note of urgency) active imperative of δοξαζω and in the sense of his death already in verses 16,23 and again in 13:31; 17:5. This is the prayer of the πνευμα (or ψυχη) as opposed to that of the σαρξ (flesh) in verse 27. The "name" (ονομα) of God expresses the character of God (1:12; 5:43; 17:11). Cf. Matthew 6:9.

A voice out of heaven (φωνη εκ του ουρανου). This was the Father's answer to the prayer of Jesus for help. See already the Father's voice at the baptism of Jesus and at the transfiguration . The rabbis called the audible voice of God bath-qol (the daughter of a voice).

I have both glorified it and will glorify it again (κα εδοξασα κα παλιν δοξασω). This definite assurance from the Father will nerve the soul of Jesus for the coming ordeal. Cf. 11:40 for εδοξασα and 13:31; 17:5 for δοξασω.